Cleansing sheet-zinc.



. PATENTED AUG. so, 1904. J. NELSON.

GLEANSING SHEET ZINC..

,PPLIOATION FILED APB. 30,-1903.

No MODEL.

UNITED STATES Patented August 30, 1904.

" Arnim Orifice,y

JOHN NELSON, OF PER-U, ILLINOIS, ASSICr-NOR TO AMERICAN NICKELOID & MANUFACTURING COMPANY, OF PERU, ILLINOIS, A CORPORATION OF ILLINOIS.

CLEANSING ASHEET-ZINC.

.SPECIFICATION forming part of Letters Patent No. 768,818, dated August 30, 1904.

Application filed April 30, 1903. Serial No. 154,988.

To (all lull/0771, it muy concern:

Be it known that I, J oHN'N ELsoN, a citizen of the United States, residing at Peru, in the county of Lasalle and State of Illinois, have invented a new and useful Improvement in Cleansing Sheet-Zinc, of which the following is a specification.

My invention relates particularly to means for and methods of treating sheet-Zinc pre paratory to plating the same.

My primary object is to provide a composition or bath adapted to the purpose mentioned, an improved method of cleansing sheet-Zinc, and improved apparatus for carrying out the method.

The apparatus forcarrying out the improved method is illustrated in the accompanying drawings, in whiche Figure l represents a transverse vertical section of the apparatus, and Fig. 2 asectional perspective view of an anode employed.

A represents a tank, which may beof wood;

C C (f C, anodes located .in said tank; I) D D2, a series of longitudinal bars serving to support sheets of zinc D, and E a dynamo having its positive pole connected with the anodes and its negative pole connected with the rods D D I)2f The anodes comprise longitudinally corrugated sheet -iron members equipped at intervals with vertical cleats a of wood or other non-conducting material. The anodes C C3 constitute linings for the sides of the tank and have cleats on one side only. The remaining anodes are cleated on both sides andare preferably separated froml each other and from the side anodes by spaces of about twelve inches. ported about four inches above the tank midway between the anodes. Then the sheets of zinc are to be plated on one side only, they are arranged in pairs back to back before immer'sion in the cleansing-bath.

The improved process is carried out by employing the sheets of zinc as cathodes, immersing them in an alkaline bath, and passing an electric current in the manner indicated. A'solution well adapted to the purpose has the following composition: one gallon water The rods are sup- (No specimens.)

best results, and for cleansing three pairs or sheets with six exposed surfaces of three feet by seven feet a current of about four hundred zinc sheets and any dirt present being loosened and falling to the bottom of the tank. The chief function of the ammonium hydrate is to prevent the escape of a noxious gas during the electrolytic action, although ammonium is in itself a good solvent of grease.

It appears to be unnecessary to set forth the chemical reactions concerned in the process, as most of them will be readily understood when once the method is known, and there is still some doubt as to the nature of others.

It is noteworthy that in my improved process no acid is brought into contact with the sheets of zinc-such, for instance, as would occur if the current were reversed and the cyanid ion (CN) liberated, having aflinity for the plus pole, were freed at the (now) zinc anodes. Moreover, no such salts are employed as might supply acids which would attack lthe iron anodes. I refer t0 sodium chlorid and other salts of like nature.

The corrugations of the anodes increase the area thereof, and the vertical cleats of wood prevent short-circuiting at the bath.

The eect of subjecting the sheets of zinc to the electrolytic action of a bath ofthe nature described is to cause them to be thoroughly cleaned withouthaving their polish destroyed,

which would occur il the Zinc were to he attacked by an acid. The importance of this will be more readily appreciated when it is recalled that zinc is very readily attacked by the most of the acids.

Changes within the spirit of my invention are` contemlilatefl. Hence no undue limitation should be understood from the foregoing detailed description.

vWhatl regard as new, and desire to secure by Letters Patent, is*A l. Themethod ofcleansingslieet-Zinc,which consists in immersing the sheets in an alkaline bath free from compounds from which harmful acids might be formed, connecting them with the negative pole of a generator, and passing' an electric current through the bath and sheets, for the purpose set forth.

2. rl`he method of cleansing sheet-Zinc, which consists in immersing the sheets in a bath containing potassium cyanid, sodium carbonate, lye and ammonium hydrate, in proportions suited to the coating to be removed` said bath being free from compounds from which harmful acids might be formed, and passing' an electric current through the bath in the direction of the sheets and through the sheets back to the generator, for the purpose set forth.

3. The method of cleansing' sheet-zinc, which consists in immersing the sheets in a bath containing potassium cyanid and other alkaline solution, in proportions suited to the coating to be removed, said bath being free from compounds from which harmful acids might be formed, and passing an electric current through the bath in the direction of the sheets and through the sheets back to the generator.

4. The method of cleansing sheet-Zinc, which consists in immersing the sheets in a bath containingl potassium cyanid and sodium carbonate, in proportions suited to the coating' to be removed,said bath being' free from compounds from which harmful acids might be formed, and passing an electric current through the bath in the direction of the sheets and through the sheets back to the generator.

JOHN NELSON. 1n presence of-H W. B. DAvlns, WALTER N. W INB uns. 

